Potential of magnetic resonance spectroscopy in assessing the effect of fatty acids on inflammatory bowel disease in an animal model

People with inflammatory bowel disease (IBD) are at risk for developing colorectal cancer, and this risk increases at a rate of 1% per year after 8-10 years of having the disease. Saturated and ω-6 polyunsaturated fatty acids (PUFAs) have been implicated in its causation. Conversely, ω-3 PUFAs may have the potential to confer therapeutic benefit. Since proton magnetic resonance spectroscopy (¹H MRS) combined with pattern recognition methods could be a valuable adjunct to histology, the objective of this study was to analyze the potential of ¹H MRS in assessing the effect of dietary fatty acids on colonic inflammation. Forty male Sprague-Dawley rats were administered one of the following dietary regimens for 2 weeks: low-fat corn oil (ω-6), high-fat corn oil (ω-6), high-fat flaxseed oil (ω-3) or high-fat beef tallow (saturated fatty acids). Half of the animals were fed 2% carrageenan to induce colonic inflammation similar to IBD. ¹H MRS and histology were performed on ex vivo colonic samples, and the ¹H MR spectra were analyzed using a statistical classification strategy (SCS). The histological and/or MRS studies revealed that different dietary fatty acids modulate colonic inflammation differently, with high-fat corn oil being the most inflammatory and high-fat flaxseed oil the least inflammatory. ¹H MRS is capable of identifying the biochemical changes in the colonic tissue as a result of inflammation, and when combined with SCS, this technique accurately differentiated the inflamed colonic mucosa based on the severity of the inflammation. This indicates that MRS could serve as a valuable adjunct to histology in accurately assessing colonic inflammation. Our data also suggest that both the type and the amount of fatty acids in the diet are critical in modulating IBD.